<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div id="demo2">
        姓名: {{fullName}}
    </div>
<script src="https://unpkg.com/vue@2.6.1/dist/vue.min.js"></script>
<script>
    var demo2 = new Vue({
        el: '#demo2',
        data: {
            firstName: 'Jack',
            lastName: 'Green'
        },
        computed: {
            fullName:{
                //getter用于读取
                get: function() {
                    return this.firstName + ' ' + this.lastName;
                },
                //写入时触发
                set: function(newValue){
                    var names = newValue.split(' ');
                    this.firstName = names[0];
                    this.lastName = names[names.length - 1];
                }
            }
        }
    });

</script>
</body>
</html>